I worked at a place that did this with their frontend app. Devs rarely knew where anything should go and so for any given Component/Module, there was usually some accompanying `MyComponent.fns.ts` file. Homes were NEVER found for it later. Code duplication through the nose and lots of spaghetti coupling.
Edit: i'm definitely blowing off some steam. That said, I think there is good virtue in this "habit" so long as there is good reason that it "doesn't fit anywhere" ... and when another module starts referencing the temporary home module, it is a smell that the time is now to give it a proper home.